Electrical Systems and Energy Infrastructure Flashcards

Vocabulary based on lecture notes covering electrical circuits, emissions scopes, power infrastructure, battery technology, and modern grid concepts.

Scope 1: Direct Emissions

Emissions from sources the company directly owns or controls, such as burning fuel in company-owned vehicles, boilers, or furnaces.

Scope 2: Indirect Emissions from Purchased Energy

Indirect Emissions from Purchased Energy These are indirect emissions from the creation of electricity, steam, heating, or cooling that the company purchases for its own operations.

Examples:The electricity used to power a company's offices, factories, or data centers.The heat and cooling required for a company's buildings and facilities.

Scope 3: Other Indirect Emissions

Broad category including indirect emissions occurring in a company's value chain outside its direct control, such as upstream production of materials or downstream use of sold products.

Examples: Upstream activities: Emissions from the production of purchased goods and materials (e.g., metals for a car manufacturer), upstream transportation (e.g., transporting components to a factory), and employee commuting.Downstream activities: Emissions from the use of sold products (e.g., consumers cooking a product), and the end-of-life treatment of products (e.g., recycling or landfilling waste from products).Other examples include business travel, waste disposal, and capital goods.

Circuit

A closed, continuous pathway that allows electricity (electrons) to flow from a power source, through components, and back to the source. It requires a complete loop to function; if the path is broken (open circuit), electricity cannot flow.

Key Components of a Circuit

• Power Source: Provides voltage/energy (e.g., battery, outlet).

• Conductor: Material allowing electron flow, typically copper wires.

• Load: Device consuming power (e.g., light bulb, motor, resistor).

• Switch: Controls the circuit by opening or closing the path.

Key Concept

• Voltage (): The "push" that makes electricity flow, measured in volts.

  
  

• Current (): The flow rate of charge, measured in amperes (amps).

  
  

• Resistance (): Opposition to the flow of charge, measured in ohms ()

Voltage

The "push" or electrical potential difference that makes electricity flow, that drives electric charge to move through a circuit, measured in volts ($V$).

Requirement: Must have a difference in potential (voltage) between two points for current to flow. Think one end of a pipe higher than the other that causes the water to flow down.

Often compared to water pressure in a pipe, it represents the energy available to push current from one point to another, generated by sources like batteries.

Wall outlet supplies 120V AC. There is the voltage supplied to the thing, and the voltage it outputs or uses. Ie. a phone charger outputs 5-20v.

Many devices do use a transformer or transformer-like component to reduce the voltage, but not all modern electronics use a traditional transformer. Voltage conversion is one of the primary jobs of power electronics.

Current ($I$)

An amp (ampere) is a unit measuring the rate of electrical current, essentially how many electrons flow past a point in a wire per second, like the flow rate of water in a pipe. It tells you the "volume" or "amount" of electricity moving, with higher amps meaning more current, which determines how much power a device needs or how much a wire can safely carry.

Relation to Watts: Amps multiplied by volts (pressure) equals watts (power).

Resistance ($R$)

Opposition to the flow of charge, measured in ohms ($\Omega$).

Watts ($W$)

A unit of power measuring the rate at which energy is used or produced; calculated in simple circuits as $W = V \times A$ .

Analogy: Think of it like speed (miles per hour) for electricity, telling you how fast the energy is flowing.

Higher wattage means more power, so a 100-watt light bulb uses more power than a 60-watt bulb, and larger devices use kilowatts (kW).

W is for things like light bulbs, Kw is next like microwave, then mw which is like solar installations, then gw.

K-kilo, 1,000 watts

M-mega, 1,000,000 watts, 1 million watts

G-giga, 1,000,000,000 watts, 1 billion watts

Battery Power and Energy Capacity

For batteries it depends how long the battery can discharge energy. So, a battery with a power capacity of 1 MW that can typically operate for 4 hours (duration) would have an energy capacity of 4 MWh battery (1 MW x 4 hours = 4 MW-hours).

Or a battery system has a power rating of 30 MW and an energy rating of 120 MWh. This means the battery can discharge for 4 hours.

Switchgear

An electrical device or assembly used to control, protect, and isolate electrical equipment in a power system, acting as a command center for distribution.

Switchgear is like the breaker box or control panel in a building—but scaled up for industrial, utility, or large commercial use. It helps manage where electricity flows, and protects circuits from overloads or faults.

Key functions of switchgear:

1. Control – Turns electrical circuits on or off.

2. Protection – Detects faults (like a short circuit or overload) and automatically shuts off power to prevent damage or fire.

3. Isolation – Lets maintenance crews safely disconnect equipment from the power supply.

Power Grid

The power grid is the system that delivers electricity from where it's made—like power plants or solar farms—to homes, businesses, and other places that use it. It includes power lines, transformers, and control systems that help move and manage electricity safely and reliably across long distances.

And if you want an even more relatable version:

The power grid is like the highway system for electricity. It moves power from where it's made to where it’s needed, and keeps everything running smoothly so our lights stay on and devices work.

Power Electronics

Power electronics is a branch of electrical engineering that uses solid-state electronics (semiconductor switches like diodes and transistors) to convert, control, and manage electrical power efficiently. It acts as an interface between an energy source and a load, modifying voltage, current, and frequency to meet specific requirements.

The growing emphasis on electrification for a cleaner environment has increased the demand for electric power in various forms. Power electronics focuses on managing high voltages and currents to deliver power tailored to different needs. Whether for household devices or equipment used in space, all these applications require stable and reliable electric power with specific characteristics.

UPS (Uninterruptible Power Supply)

A device providing emergency backup power to equipment when the main power source fails, allowing for safe shutdown or switching to a generator.

A UPS is like a battery-powered safety net for your electronics—it keeps things running for a short time if the power goes out, long enough to shut down safely or switch to a generator.

Transformer

A device that changes the voltage level of electricity, either stepping it up for efficient long-distance transmission or down for safe home use.

In layman’s terms
Think of electricity like water flowing through pipes:

Voltage is like the water pressure.

Sometimes you need high pressure to send water long distances (power lines).

Sometimes you need low pressure so you don’t break your sink or hose (home appliances).

A transformer is like a pressure adapter — it takes in electricity at one “pressure” and sends it out at another, so it’s safe and efficient for the job.

Inverters

Devices that convert electricity from Direct Current ($DC$) into Alternating Current ($AC$).

DC power flows in one direction (steady), like what comes from solar panels, batteries, or a car’s electrical system.

AC power changes direction many times a second (in the U.S., 60 times a second), and it’s what comes out of wall outlets and runs most household appliances.

Think of DC as water flowing smoothly in one direction down a pipe. AC is like water sloshing back and forth rhythmically. Most of our power system — and the devices in our homes — are designed for the sloshing kind.

Where you’ll see inverters:

Solar power systems — to convert the DC from panels into AC for your home or the grid

Battery storage — to send stored DC power back out as AC

Electric vehicles — to run AC motors from DC batteries (and sometimes to send AC back to the grid)

Portable power stations — to plug in normal AC devices

Rectifiers

A rectifier is basically the opposite of an inverter — it changes alternating current (AC) into direct current (DC).

What it does
Takes AC power (like what comes from the wall or a generator)

Converts it into DC power (a steady, one-direction flow)

Often also smooths the output so it’s stable enough for electronics or charging batteries

Where you’ll see rectifiers
Battery chargers — to turn AC from the outlet into DC the battery can store

Power supplies for electronics — your phone charger, laptop brick, or desktop PC all have rectifiers inside

DC equipment — motors, LED lighting, electroplating systems, etc. that run on DC but are powered from the AC grid

Batteries use direct current

Direct Current ($DC$) and Batteries

A steady, unidirectional flow of electricity from the positive to the negative terminal; the type of power produced and used by all batteries.

Think of DC as water flowing smoothly in one direction down a pipe. AC is like water sloshing back and forth rhythmically. Most of our power system — and the devices in our homes — are designed for the sloshing kind.

Yes, all batteries produce direct current (DC), meaning electricity flows in only one direction from the positive to the negative terminal. Because batteries rely on chemical reactions to move electrons, they cannot produce alternating current (AC), which requires switching polarity. While batteries store and deliver DC, they are often charged using AC-to-DC converters. 

If a battery-powered device is used with an AC outlet, a converter or inverter is used within the charging circuit to turn the AC power into the DC power the battery needs.

Peak Shaving

The practice of reducing the highest spikes in electricity demand to even out usage over time, lowering costs and reducing strain on the grid.

In simple terms:

• Without peak shaving – you might have short periods where you draw a lot of power all at once (for example, charging multiple CEVs at maximum rate simultaneously). These peaks can be expensive because utilities often charge extra for the highest demand period, and they can also strain the grid.

• With peak shaving – you intentionally spread out or shift those energy-intensive activities (like charging) so your demand never hits those high spikes. This can lower costs, reduce strain on the system, and sometimes allow you to operate within grid or equipment constraints.

Load

Anything in an electrical system that consumes power, such as lights, motors, or HVAC units, measured in kilowatts ($kW$) or megawatts ($MW$).

Load Bank

A load bank is a device that mimics an electrical load for testing purposes — without needing to hook up actual equipment.

• Purpose: It allows you to test generators, batteries, or other power systems under controlled conditions.

• How it works: The load bank applies an electrical demand (often adjustable) to the system, measuring how it performs under specific loads.

• Use cases:

  • Verifying that a generator can handle its rated power.

  • Testing battery discharge performance.

  • Training operators without risking real equipment.

Load Bank Software

This is software that controls and monitors the load bank.

• Functions:

  • Set and adjust the load (e.g., apply 25%, 50%, 100% load).

  • Schedule load changes over time (e.g., ramp up gradually).

  • Collect and store performance data (voltage, current, frequency, temperature, etc.).

  • Generate reports for compliance or troubleshooting.

UL (Underwriters Laboratories) & UL Testing

An independent global safety science company that tests and evaluates products to ensure they meet specific safety, quality, and performance standards.

UL certification is a process by which the independent global safety science company Underwriters Laboratories (UL) tests and evaluates products to ensure they meet specific safety, quality, and performance standards. A product bearing a UL mark, such as the UL Listed or UL Recognized Component mark, indicates it has undergone rigorous testing and that the manufacturer is committed to safety and quality. 

Ion

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons. Unlike neutral atoms, which have equal protons and electrons, ions have unequal numbers, resulting in a positive charge (cation) or negative charge (anion)

Cathode & Anode

• Cathode: the positive side of a battery during use. It’s where electrons arrive after doing work in your device.

• Anode: the negative side of a battery during use. It’s where electrons leave to power your device, and they go through a circuit.

Think of a battery like a tiny city:

• Electrons are commuters.

• The anode is the busy parking garage they drive out of (source of electrons).

• The cathode is the office building they drive into (where electrons end up).

Inside the battery, ions (charged atoms, like lithium ions) move through the battery’s liquid/solid interior, while electrons go the long way around through your device to do useful work.

One wrinkle: in rechargeable batteries, the roles flip during charging (electrons are pushed back the other way), but during discharging—the normal “powering your device” mode—the anode is negative and the cathode is positive.

Flow Battery

Flow batteries store energy in tanks of liquid electrolyte, with separate power stacks. This means that, unlike lithium-ion (Li-ion) batteries, where the energy and power are both within the cell, flow batteries enable the decoupling of energy and power.

What this means in effect is that the energy capacity of a flow battery can be scaled up simply by increasing the size of the electrolyte tanks, lowering the cost of increasing the system’s duration.

Point of Common Coupling (PCC)

The specific, physical location in an electrical system where a customer's private, local grid (such as a factory, home, or microgrid) connects to the public utility’s network. It acts as the legal and technical demarcation point for power quality, voltage stability, and, commonly, revenue metering.

Wikipedia

Key Aspects of the Point of Common Coupling (PCC):

• Boundary of Responsibility: The PCC defines where the utility's responsibility for power delivery ends and the customer’s responsibility for their internal power quality begins.

• Location: Typically found at the customer-side of the utility revenue meter, the service transformer’s secondary terminals, or the main service entrance.

• Power Quality and Harmonics: It is the reference point for ensuring the electrical load does not introduce harmful harmonics or voltage distortions that could affect neighboring customers.

• Distributed Energy Resources (DERs): For installations with solar panels or wind turbines, the PCC is the point where locally generated power is injected into the public grid.

• Compliance: The PCC is where grid standards and codes, such as IEEE 519 (for harmonics) or IEEE 1547 (for DERs), are measured and enforced.

IEEE

The Institute of Electrical and Electronics Engineers, a leading consensus-building organization for advancing global technologies and standards.

IEEE 2030.6

A guide for monitoring and evaluating the effects and benefits of electric power grid customer demand response programs.

Power Quality

Power quality refers to faults like sags and swells. You expect 12 kV throughout the microgrid, or, for your phone, 120 volts at the outlet. But if you measure it, you’ll see swells or sags—135 or 118—which isn’t ideal. Electronics have an operating range; outside that range you can fry them. Another example: power should be 60 Hz, but when you discharge a battery you can get harmonics—electricity at different frequencies. Those other frequencies aren’t useful and can cause electronics to trip.

Power quality (PQ) defines how closely the voltage, frequency, and waveform of a power supply match ideal standards, ensuring electrical equipment operates correctly without failure or degradation. It measures the compatibility between the supplied electrical energy and the sensitive load, covering voltage, current, and frequency stability.

Power Harmonics

Power harmonics are “extra” frequencies that show up in electricity when the power waveform isn’t a perfectly smooth 60 Hz sine wave. Inverter-based equipment (like batteries and EV chargers) creates power using electronics that can introduce small distortions, which can lead to overheating, reduced power quality, and sensitive equipment (like elevator or HVAC variable-frequency drives) tripping—so engineers monitor and limit this using measures like total harmonic distortion (THD).

Generator power (the classic “spinning” kind) is usually cleaner because the electricity is produced by a rotating machine, which naturally generates a smooth 60 Hz sine wave.

Battery systems and many modern chargers are inverter-based: they don’t spin to create AC power. They start with DC (from the battery) and use power electronics to synthesize an AC waveform. That synthetic waveform is very good, but it’s often built from high-frequency switching and “stepped” approximations of a sine wave. Those tiny imperfections show up as harmonics (extra frequency components), which can degrade power quality and bother sensitive equipment.

So the difference is basically:

• Generators: smooth, naturally sinusoidal output from rotation → typically fewer harmonics.

• Inverters: electronically “constructed” waveform via switching → more risk of harmonics unless carefully filtered and controlled.

Distributed Energy Resource (DER)

Small-scale, localized power generation and storage technologies (like rooftop solar or batteries) located near the point of consumption.

Grid Forming vs Grid Following

Grid forming is a term that refers to the ability of an inverter-based energy source, such as solar, wind, or battery, to provide voltage and frequency support to the grid, especially during disturbances or outages. Grid forming inverters can operate independently or in coordination with other sources, and can help restore the grid after a blackout. Grid forming is a key technology for integrating more renewable energy into the grid and ensuring its reliability and stability.

Grid following is a term that refers to the control strategy of an inverter-based energy source, such as solar, wind, or battery, that synchronizes its output with the grid voltage and frequency. Grid following inverters are current sources that track the grid angle and magnitude to inject or absorb active and reactive power. Grid following inverters depend on the grid to provide a stable voltage and frequency reference, and cannot operate in islanded or off-grid mode.

Microgrid

A microgrid is a self-sufficient energy system that serves a discrete geographic footprint, such as a college campus, hospital complex, business center or neighborhood.

Within microgrids are one or more kinds of distributed energy (solar panels, wind turbines, combined heat and power, generators) that produce its power. In addition, many newer microgrids contain energy storage, typically from batteries. Some also now have electric vehicle charging stations.

Interconnected to nearby buildings, the microgrid provides electricity and possibly heat and cooling for its customers, delivered via sophisticated software and control systems.

Microgrid defined by three key characteristics

1. A microgrid is local

First, this is a form of local energy, meaning it creates energy for nearby customers. This distinguishes microgrids from the kind of large centralized grids that have provided most of our electricity for the last century. Central grids push electricity from power plants over long distances via transmission and distribution lines. Delivering power from afar is inefficient because some of the electricity – as much as 8% to 15% – dissipates in transit. A microgrid overcomes this inefficiency by generating power close to those it serves; the generators are near or within the building, or in the case of solar panels, on the roof.

1. A microgrid is independent

Second, a microgrid can disconnect from the central grid and operate independently. This islanding capability allows it to supply power to its customers when a storm or other calamity causes an outage on the power grid. In the US, the central grid is especially prone to outages because of its sheer size and interconnectedness – more than 5.7 million miles of transmission and distribution lines. As we learned painfully during what’s known as the Northeast Blackout of 2003, a single tree falling on a power line can knock out power in several states, even across international boundaries into Canada. By islanding, a microgrid escapes such cascading grid failures.

While microgrids can run independently, most of the time they do not (unless they are located in a remote area where there is no central grid or an unreliable one). Instead, microgrids typically remain connected to the central grid. As long as the central grid is operating normally, the two function in a kind of symbiotic relationship, as explained below.

1. A microgrid is intelligent

Third, a microgrid – especially advanced systems – is intelligent. This intelligence emanates from what’s known as the microgrid controller, the central brain of the system, which manages the generators, batteries and nearby building energy systems with a high degree of sophistication. The controller orchestrates multiple resources to meet the energy goals established by the microgrid’s customers. They may be trying to achieve lowest prices, cleanest energy, greatest electric reliability or some other outcome. The controller achieves these goals by increasing or decreasing use of any of the microgrid’s resources – or combinations of those resources – much as a conductor would call upon various musicians to heighten, lower or stop playing their instruments for maximum effect.

A software-based system, the controller can manage energy supply in many different ways. But here’s one example. An advanced controller can track real-time changes in the power prices on the central grid. (Wholesale electricity prices fluctuate constantly based on electricity supply and demand.) If energy prices are inexpensive at any point, it may choose to buy power from the central grid to serve its customers, rather than use energy from, say, its own solar panels. The microgrid’s solar panels could instead charge its battery systems. Later in the day, when grid power becomes expensive, the microgrid may discharge its batteries rather than use grid power.

Microgrids may contain other energy resources – combined heat and power, wind power, reciprocating engine generators, fuel cells – that add even greater complexity and nuance to these permutations.

Working together via complex algorithms, the microgrid’s resources create a whole that is greater than the sum of its parts. They drive system performance to a level of efficiency none could do alone. All of this orchestration is managed in a near instantaneous fashion – autonomously. There is no need for human intervention.

Virtual Power Plant (VPP)

A Virtual Power Plant (VPP) is a cloud-based network of decentralized, small-scale energy resources—such as home solar batteries, electric vehicles (EVs), and smart thermostats—that are aggregated to operate as a single, flexible power plant. Using software to coordinate in real time, VPPs balance electricity supply and demand, supplying power to the grid during high-demand events while rewarding participants. Wikipedia +5

Wikipedia

Key Aspects of Virtual Power Plants:

• Components: VPPs bundle together distributed energy resources (DERs) including residential battery storage, rooftop solar, smart HVAC systems, and bidirectional EV chargers

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Functionality: Unlike a physical power plant, a VPP is a software-driven, digital network that aggregates capacity to provide reliability, stability, and energy to the grid.

• Functionality: Unlike a physical power plant, a VPP is a software-driven, digital network that aggregates capacity to provide reliability, stability, and energy to the grid.

Benefits:
◦ For the Grid: Increases reliability by providing, reducing, or storing electricity during shortages.
◦ For Participants: Allows homeowners to monetize their energy devices by selling stored or generated power back to the utility.
◦ Environmental: Reduces reliance on traditional fossil fuel peaker plants, lowering emissions.

Operation: A central control system monitors, forecasts, and manages the network, ensuring the aggregated resources act in unison to meet grid needs. RMI +9

• Operation: A central control system monitors, forecasts, and manages the network, ensuring the aggregated resources act in unison to meet grid needs.

RMI

VPPs enable a cleaner, more efficient energy transition by utilizing existing, private infrastructure to support public grid demand.

Power Purchase Agreement (PPA)

A long-term contract where a developer installs and operates a renewable energy system on a customer's property and sells the power at fixed rates.

Key Aspects of a PPA:

• No Upfront Costs: The developer covers all design, permitting, and installation costs.

• Lower Energy Costs: Customers often pay a lower, more stable rate for electricity than from the local utility.

• Ownership:

  The third-party developer owns and maintains the system, assuming all performance risks

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Ownership End-of-Term: At the end of the contract, the buyer may have options to renew, remove, or purchase the system at fair market value.

• Ownership End-of-Term: At the end of the contract, the buyer may have options to renew, remove, or purchase the system at fair market value.

12kV Line

A medium-voltage electrical backbone distribution system that moves large amounts of electricity efficiently before being stepped down for building use.

The 12kV system:

• Runs underground around campus

• Connects substations, switchgear, transformers, and buildings

• Feeds major facilities like SDSC

• Acts like a campus-wide electrical circulation system

Then, near or inside each building, transformers step the voltage down again to normal building voltages like:

• 480V (large equipment)

• 208V/120V (typical outlets, lighting, offices)

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Why use 12kV instead of regular building voltage

Higher voltage lets you move a lot of power with less current.

That matters because:

• Lower current = less heat loss (due to less flow resistance)

• You can distribute electricity long distances efficiently

Bidirectional Charging

Bidirectional charging allows electricity to flow in two directions: into an electric vehicle (EV) to charge the battery, and out of the EV to power external devices, your home, or the electrical grid. It essentially turns your car into a giant, mobile battery on wheels.
How It Works

Vehicles store electricity as Direct Current (DC), but the power grid and your home appliances use Alternating Current (AC). Bidirectional charging requires a specialized charger or the vehicle's onboard technology to convert the DC energy back into AC so it can be safely utilized externally.

To utilize bidirectional charging, you generally need three things:
A compatible EV: Not all electric cars are wired to discharge energy. Vehicles like the Ford F-150 Lightning, Hyundai Ioniq 5, Kia EV9, and Nissan Leaf (using CHAdeMO) offer varying levels of this technology.
A bidirectional charger: You will need a smart, two-way charger (such as the Wallbox Quasar 2 or units from Enphase) capable of safely converting and routing the power.
Utility approval: For home and grid integration, you typically need to coordinate with your local utility company and install specialized meters for safety.

Feeder

In utility infrastructure, a feeder (or feeder line) is a medium-voltage electrical power line that transmits electricity from a distribution substation to local distribution points or transformers. Think of it as the "main highway" of the neighborhood power grid, moving bulk power safely into neighborhoods before it gets split up into individual street lines

Relationship between Power, Voltage, and Current

Power ($P$) is calculated as the product of Voltage ($V$) and Current ($I$) in an electrical circuit, expressed as $P = V \times I$.

If you want to deliver the same amount of power, you can either use: high voltage and low current, or low voltage and high current.

The wires themselves have electrical resistance. Whenever current flows through a wire, some energy is lost as heat. The higher the current, the greater the loss, at exponential levels. The higher voltage means much lower current for the same power, dramatically reducing transmission losses.

Thus, utilities use high voltage and low current.

Relationship between Current and speed

A lower current means slower movement of electrons, called drift velocity. They can move between a few millimeters per second in a household wire (taking hours to travel from light switch to bedside lamp), or a few centimeters per second.

Another speed is the electrical signal. When you flip a light switch, the lamp turns on almost instantly—not because electrons race from the switch to the bulb, but because the electric field that tells electrons to move propagates through the wire at 50-99% of the speed of light.

Another speed is the energy that powers the lamp. It travels with the electromagnetic field surrounding the wires, not by waiting for a particular electron to make the journey.

A good analogy is a long tube filled with marbles:

• Push one marble in one end.

• A marble pops out the other end almost immediately.

• No single marble traveled the whole length instantly; the push was transmitted through the line of marbles.

CAISO

CAISO stands for the California Independent System Operator. It is a non-profit organization that manages the high-voltage electricity grid and wholesale power market for about 80% of California and a small part of Nevada. Think of it as an air traffic controller for electricity. [1, 2, 3, 4]

Key Responsibilities

• Balancing the Grid: Continuously matches electricity supply and demand in real time to keep the system stable and prevent blackouts.

• Wholesale Market: Runs a competitive market where energy buyers and sellers trade wholesale power.

• Transmission Planning: Oversees high-voltage, long-distance power lines and plans for future grid reliability and clean energy goals.

CAISO is independent of the utility companies (like PG&E, SDG&E, and SCE) that own the physical poles and wires. It is regulated at the federal level by the Federal Energy Regulatory Commission (FERC).

Power (watts) vs Energy (kWh)

Watts measure power (the rate of energy use), while kilowatt-hours (kWh) measure energy (total usage over time, as on a utility bill).

Power=volts x current

Power is the rate of energy transfer, ie. how fast you’re using or delivering energy, how fast the energy moves. Power tells you how fast a battery can discharge energy.

Energy is power used over time.

Picture a faucet filling a bathtub. Power is how fast the water comes out. Energy is how much water ends up in the tub after some time.

Resource Adequacy

Resource adequacy is the ability of an electrical power grid to supply enough electricity to meet customer demand at all times.

How Resource Adequacy Works

• Matching Supply and Demand: Grid operators look ahead to make sure power plants, energy storage, and power lines can handle the electricity people need.

• Planning Margins: Regulators set rules, like a 15% reserve margin, requiring utilities to own or buy more capacity than what normal peak hours require.

• Modern Challenges

  • Renewable Energy Transition: Moving from coal and gas to wind and solar makes power supply more variable.

  • Extreme Weather: Heatwaves and winter storms drive up demand while straining power lines and generators.

CAISO

CAISO stands for the California Independent System Operator.

It is a non-profit organization that manages the high-voltage electricity grid and wholesale power market for about 80% of California and a small part of Nevada. Think of it as an air traffic controller for electricity.

Key Responsibilities:

• Balancing the Grid: Continuously matches electricity supply and demand in real time to keep the system stable and prevent blackouts.

• Wholesale Market: Runs a competitive market where energy buyers and sellers trade wholesale power.

• Transmission Planning: Oversees high-voltage, long-distance power lines and plans for future grid reliability and clean energy goals.

Public Utilities Commission (PUC)

A state-level government regulatory body that oversees privately owned public utilities—such as electric, natural gas, railroad, telecommunications, and water companies—to ensure consumers receive safe, reliable service at reasonable rates.

What the CPUC Does

• Sets Rates: Ensures utility service and infrastructure costs remain reasonable for consumers.

• Ensures Safety: Monitors operations for safety and reliability across energy, water, and transit networks.

• Regulates Transport: Oversees common carriers, passenger carriers, railroads, and rideshare services.

• Protects Consumers: Guards against fraud and enforces service standards.

Leadership and Structure

• Commissioners: Five members appointed by the Governor and confirmed by the state Senate for staggered six-year terms.

• Operations: Supported by divisions of specialized engineers, lawyers, economists, and safety experts.

• Public Advocates Office: An independent arm within the agency that specifically champions the interests of utility ratepayers